tbuckley/cabot-search huggingface dataset:
EXTH-36. MRGFUS-DELIVERED FLUORESCENT EGFR/EGFRVIII ANTIBODY ENABLES THERANOSTIC IMAGING OF PEDIATRIC HIGH-GRADE GLIOMA AND PREDICTS RESPONSE TO TARGETED THERAPY
Authors: Quan Zhou, Muna Aryal, Johana Vega Leonel, Michelle Santoso, Aimen Zlitni, Hannes Vogel, Romain Cayrol, Gordon Li, Michael Moseley
Journal: Neuro-Oncology (2022)

Abstract BACKGROUND Pediatric high-grade glioma (pHGG) consists of the deadliest childhood brain cancers refractory to current therapies. Fluorescent antibodies against epidermal growth factor receptor (EGFR) have demonstrated clinical promise in image-guided surgery of adult gliomas. However, their potential theranostic use for pHGG remains unexamined. This study evaluated an EGFR/EGFRvIII-targeted imaging and treatment strategy as an alternative therapeutic approach for pHGG using tracer amount of fluorescent antibody delivered through blood-brain barrier modulation. METHODS Immunohistochemical stainings of EGFR, EGFRvIII and claudin-5 were performed on pHGG patient tissue (n = 66). In vitro competition assay assessed binding affinity of panitumumab-IRDye800 for EGFR/EGFRvIII on pHGG cells whose viability was measured upon panitumumab treatment. Mice with EGFR/EGFRvIII-positive orthotopic pHGG patient-derived xenografts received 1 mg/kg panitumumab-IRDye800 20 hours after transcranial magnetic resonance-guided focused ultrasound (MRgFUS) sonication (2 min at 0.25 MPa). Near-infrared fluorescence imaging measured tumor-to-background ratio and TUNEL assay determined apoptotic rate in resected tumor. Survival was documented for 60 days in pHGG-bearing mice receiving 1 mg/kg panitumumab weekly with or without MRgFUS. RESULTS 61% and 24% pHGG patient tissue respectively expressed EGFR and EGFRvIII (17% expressing both). Heterogeneous claudin-5 expression indicated partial blood-brain barrier permeability. Panitumumab-IRDye800 bound to EGFR/EGFRvIII-positive pHGG with high affinity (IC50: 4.2 nM). EGFR blocking enhanced therapeutic response of panitumumab by 48 ± 13%. Following MRgFUS in pHGG-bearing mice, 19 ± 6.3% injected dose of intratumoral panitumumab-IRDye800 uptake resulted in 2.1 ± 0.4 tumor contrast and 3.9 ± 1.1% apoptotic cell death. Weekly MRgFUS with 1 mg/kg panitumumab prolonged median survival (27.5 vs. 17.5 days, P &amp;lt; 0.0001, n = 10). CONCLUSION Tracer dose of panitumumab-IRDye800 improved tumor contrast and predicted antitumor activity via EGFR/EGFRvIII dual targeting following MRgFUS, potentially benefiting 68% of pHGG population. Reduced therapeutic dose of panitumumab by EGFRvIII-focused targeting may improve treatment safety and efficacy against EGFRvIII-stratified gliomas.
CTNI-31. COG ACNS1721: PHASE 2 STUDY OF VELIPARIB AND LOCAL IRRADIATION, FOLLOWED BY MAINTENANCE VELIPARIB AND TEMOZOLOMIDE, IN PATIENTS WITH NEWLY DIAGNOSED HIGH-GRADE GLIOMA WITHOUT H3 K27M OR BRAF MUTATIONS
Authors: Matthias Karajannis, Arzu Onar Thomas, Patricia Baxter, Nina Butingan, Christine Fuller, Amar Gajjar, Sofia Haque, Nada Jabado, Tong Lin, John Lucas, Shannon MacDonald, Celeste Matsushima, Namrata Patel, Christopher Pierson, Linda Springer, Eileen Stark, Mark Souweidane, Michael Walsh, Wafik Zaky, Maryam Fouladi, Kenneth Cohen
Journal: Neuro-Oncology (2022)

Abstract BACKGROUND The outcome for pediatric patients with high-grade glioma (HGG) remains poor. Veliparib, a potent oral PARP1/2 inhibitor, enhances the activity of radiotherapy and DNA-damaging chemotherapy. Preclinical data indicates that veliparib crosses the blood-brain-barrier and enhances the efficacy of radiotherapy and temozolomide in IDH mutant and wild-type HGG models. ACNS1721 was a single-arm, non-randomized phase 2 clinical trial designed to determine whether treatment with veliparib and radiotherapy, followed by the poly (ADP-ribose) polymerase (PARP) inhibitor veliparib and temozolomide, improves progression-free survival (PFS) in pediatric patients with newly diagnosed HGG without H3 K27M or BRAF mutations compared to patient level data from historical cohorts with closely matching clinical and molecular features. METHODS Following surgical resection, newly diagnosed children with non-metastatic HGG were screened by rapid central pathology review and molecular testing. Eligible patients without somatic H3 K27M or BRAF mutations were enrolled on Stratum 1 (IDH wild-type) or Stratum 2 (IDH mutant). Protocol radiochemotherapy consisted of involved field radiotherapy with concurrent veliparib at 65 mg/m2 twice daily. Adjuvant chemotherapy consisted of up to 10 cycles of veliparib 25 mg/m2 twice daily and temozolomide 135 mg/m2 once daily for 5 days every 4 weeks. RESULTS Both strata were closed to accrual for futility after planned interim analyses. Among the 23 eligible patients who enrolled on Stratum 1 and received protocol therapy, the 1-year progression-free survival (PFS) was 0.29 (SE = 0.09) and 1-year overall survival (OS) was 0.67 (SE = 0.10). Among the 14 eligible patients who enrolled on Stratum 2 and received protocol therapy, the 1-year PFS was 0.57 (SE = 0.15) and 1-year OS was 0.90 (SE = 0.09). CONCLUSION Rapid central pathology review and molecular testing was feasible. The protocol therapy was well tolerated but failed to improve outcome compared to clinically and molecularly matched historical control cohorts.
BIOM-09. GUIDING PRECISION THERAPEUTICS THROUGH INTERROGATING ONCOGENIC PATHWAY ACTIVATION
Authors: Liana Nobre, Adrian Levine, Scott Milos, Monique Johnson, Ben Laxer, Scott Ryall, Julie Bennett, Michelle Ku, Robert Siddaway, Uri Tabori, Cynthia Hawkins
Journal: Neuro-Oncology (2022)

Abstract The deregulation of canonical oncogenic pathways are largely responsible for driving pediatric cancers and can be targeted for therapeutics. Currently, we interrogate these pathways clinically by looking for gene mutations, but these are not found in all cases, and in others multiple genes are. We hypothesized that assessing transcriptomic and proteomic-based pathway activation will allow a better understanding of the most active oncogenic pathways and help guide therapy. To do this, we developed and validated a nanostring based assay that interrogates 4 key actionable pathways (MAPK, PI3K-AKT-mTOR, JAK-STAT, and NFkB) including RNA, protein and phosphoprotein expression. The assay was clinically validated using isogenic cell lines and a cohort of 40 gliomas with previous RNAseq. We then interrogated over 400 tumor samples, including 15 ependymomas, 11 medulloblastomas, 250 low grade gliomas (LGG), 145 high grade gliomas and 10 control normal brain specimens. Interestingly, although pediatric LGG exhibited higher MAPK activation than control tissue and other tumor types, a subset of these tumors have increased activity in PI3K , JAK and NFKB pathways. Furthermore, high PI3K activation score was correlated with worse PFS in a subset of pediatric LGGs that required adjuvant chemotherapy (p=0.018). To further explore the therapeutic implication of the assay, we analyzed a cohort of patients treated with MEK inhibitors (n=20). Strikingly, on top of universal RAS/MAPK activation, crosstalk between additional activated pathways such as PI3K and JAK-STAT may contribute to lack of response. In particular, pre-treatment and post-progression PLGG who failed therapy, revealed mild reduction in MAPK signature accompanied by increased PI3K phospho-proteins (p-S6/p-4EBP1,p-AKT)(p&amp;lt; 0.01). We conclude that assessing oncogenic pathway activation can add to DNA sequencing to predict different outcome and response to targeted therapies in childhood brain tumors. This can inform future therapeutic strategies including the identification of potential responders and combination strategies for non-responders.
EXTH-56. TARGETING GBM WITH AN ONCOLYTIC PICORNAVIRUS SVV-001 ALONE AND IN COMBINATION WITH FRACTIONATED RADIATION IN A NOVEL PANEL OF ORTHOTOPIC PDX MODELS
Authors: Huiyuan Zhang, Yuchen Du, Lin Qi, Sophie Xiao, Frank K Braun, Mari Kogiso, Aalaa Abdallah, Patricia A Baxter, Jack M Su, Daniel Brat, Paul L Hallenbeck, Wan-Yee Teo, Akash Patel, Xiao-Nan Li
Journal: Neuro-Oncology (2022)

Abstract BACKGROUND Large panels of clinically relevant animal models are needed for the development of new therapies for GBM. SVV-001, a replication-competent oncolytic virus that can pass through the blood brain barrier, represents an attractive novel approach. Material and METHODS Surgical tissues from 23 patients were implanted into the brains of NOD/SCID mice (1x105 cells/mouse) to develop patient-derived orthotopic xenograft (PDOX) models. Analysis of histology, gene expression (RNAseq), tumor growth was performed and compared with the patient tumors during subtransplantations (up to 5 passages). Anti-tumor activities of SVV-001 were examined in vitro in primary monolayer cultures, 3D neurospheres and purified glioma stem cells derived from 13 PDOX models; and its therapeutic efficacy validated in vivo in PDOX models through single i.v. injection (1x1011 viral particle) alone and in combination with fractionated (2 Gy/day x 5 days) radiation. Changes of animal survival times were analyzed together with viral infection, cell proliferation and DNA damage. RESULTS PDOX formation was confirmed in 17/23 (73.9%) GBMs. They replicated key histopathological features and diffuse invasion of the patient tumors. RNAseq identified the differentially expressed genes and subclassified PDOX models into proneural, classic and mesenchymal groups. SVV-001 killed primary monolayer cultures (4/13 models) and neurosphere (7/13 models) and putative glioma stem cells (CD133+ and/or CD15+ cells) in vitro, infected PDOX tumors without harming normal brain cells in vivo and significantly prolonged survival times in 2/2 models. Combination with radiation showed a trend in further prolonging animal survival times through enhanced DNA damages by SVV-001. CONCLUSION A panel of 17 clinically relevant and molecularly annotated PDOX modes of GBM is developed. The strong anti-tumor activities of SVV-001 in vitro and in vivo in GBM models provided experimental rational that support the initiation of clinical trials in GBM patients.
CTNI-35. PHASE 0/1 TRIAL OF MYCOPHENOLATE MOFETIL COMBINED WITH CHEMORADIATION TO OVERCOME TREATMENT RESISTANCE IN NEWLY DIAGNOSED AND RECURRENT GLIOBLASTOMA BY TARGETING PURINE METABOLISM
Authors: Yoshie Umemura, Wajd Al-Holou, Bernard Marini, Denise Leung, Michelle Kim, Sean Ferris, Larry Junck, Oren Sagher, Jason Heth, Yilun Sun, Matthew Schipper, Costas Lyssiotis, Theodore Lawrence, Daniel Wahl
Journal: Neuro-Oncology (2022)

Abstract BACKGROUND Purine metabolism promotes glioblastoma growth, stemness, invasiveness, and treatment resistance. The purine synthesis inhibitor, mycophenolate mofetil (MMF), improves radiation and temozolomide efficacy in preclinical glioblastoma models. This phase 0/1 trial (NCT04477200) aims to determine the maximum-tolerated dose of MMF combined with chemoradiation in glioblastoma. It also aims to quantify the levels of the active metabolite of MMF and the extent of purine synthesis inhibition in enhancing and non-enhancing tumor tissue. METHODS Key eligibility criteria are age ≥ 18 and KPS ≥ 60%. TITE-CRM dose-escalation is used for MMF dosing starting at 1000mg PO BID (range 500-2000mg BID). Thirty recurrent glioblastoma patients receive MMF one-week prior to and concurrently with re-irradiation (40.5 Gy in 15 fractions), with 28 days of dose-limiting toxicity (DLT) period. Thirty newly diagnosed glioblastoma patients receive MMF one-week prior to and concurrently with standard radiation with concurrent temozolomide and followed for 28 days for DLT1-period, then MMF is given days 0-5 of each adjuvant cyclic temozolomide using a separate dose-escalation with the first two cycles as the DLT2-period. In phase 0, eight recurrent glioblastoma patients receive MMF 500-2000mg PO BID one-week pre-operatively and tissues are analyzed using mass spectrometry. RESULTS Eighteen phase 1 subjects (11 recurrent, 7 new) have received study treatment with no DLT to date up to MMF 2000mg BID. Main toxicities are mild nausea, fatigue, and elevated liver enzymes. No notable study-related hematotoxicity nor opportunistic infection have been observed. The active metabolite of MMF accumulated to active concentrations in enhancing and non-enhancing tumor tissue and appeared to inhibit purine synthesis. CONCLUSION MMF combined with chemoradiation has been reasonably well tolerated in glioblastoma patients with preliminary evidence of intracranial target engagement of its active metabolite. This study will yield a recommended phase 2 dose and preliminary efficacy estimate for future randomized phase 2/3 trial.
EXTH-13. COMBINED TARGETING OF TELOMERASE REVERSE TRANSCRIPTASE AND METABOLISM ABROGATES GLIOBLASTOMA PROLIFERATION IN VIVO
Authors: Georgios Batsios, Meryssa Tran, Anne Marie Gillepspie, Celine Taglang, Pavithra Viswanath
Journal: Neuro-Oncology (2022)

Abstract Telomerase reverse transcriptase (TERT) is essential for tumor immortality. Since TERT is silenced in normal cells, it is an attractive therapeutic target and the TERT inhibitor 6-thio-2’-deoxyguanosine (6-thio-dG) is in clinical trials for gliomas. However, there is a lag period following TERT inhibition before tumor shrinkage is observed. Novel strategies that can be combined with TERT inhibition to enhance anti-tumor activity are sorely needed. We previously demonstrated that TERT increases expression of the alanine transporter ASCT2 in gliomas, an effect that could be non-invasively monitored using hyperpolarized 13C imaging of alanine metabolism (Viswanath et al., Nature Communications, 2021). The goals of the current study were to determine whether combined inhibition of TERT and ASCT2 inhibits GBM growth and to assess the ability of hyperpolarized [1-13C]-alanine to monitor treatment response. Our results indicated that, while both the TERT inhibitor 6-thio-dG and the ASCT2 inhibitor V-9302 individually inhibited viability, the combination of 6-thio-dG and V-9302 maximally inhibited cell viability in the patient-derived GBM1 and GBM6 models. In line with the effect on cell viability, while both compounds reduced lactate production from hyperpolarized [1-13C]-alanine, the combination of 6-thio-dG and V-9302 resulted in the highest inhibition of lactate production in both models. Importantly, treatment of rats bearing orthotopic GBM6 tumors with a combination of 6-thio-dG and V-9302 caused tumor shrinkage, an effect that could be visualized by magnetic resonance imaging by day 21 after treatment. Furthermore, lactate production from hyperpolarized [1-13C]-alanine was significantly reduced at day 7 after treatment with 6-thio-dG and V-9302, when anatomical alterations were absent. Collectively, our results indicate that simultaneously targeting TERT and ASCT2 provides a novel therapeutic opportunity for GBMs and that hyperpolarized [1-13C]-alanine serves as a companion agent for imaging early response to therapy. Our findings pave the way for precision therapy and response assessment for GBM patients.
STEM-05. GLIOBLASTOMA NEUROSPHERES DISPLAY STEMNESS CHARACTERISTICS AND UPREGULATION OF THE VEGF-A PATHWAY
Authors: Khashayar Mozaffari, Neha Chandra, Brian Aguirre, Nina Cherian, Anubhav Chandla, Madhuri Wadehra, Isaac Yang
Journal: Neuro-Oncology (2022)

Abstract INTRODUCTION Glioma stem cells (GSC) constitute a subpopulation of tumor cells with stem-cell like properties and are believed to enhance glioblastoma’s ability to grow and confer resistance against chemoradiotherapy. It has been shown that non-adherent three-dimensional (3D) growth conditions facilitate neurosphere formation and enable isolation of GSCs in vitro. This can serve as an invaluable tool to better understand the role of GSCs in glioblastoma pathogenesis. OBJECTIVE We aimed to evaluate differentially expressed genes in non-adherent versus adherent conditions using primary tumor glioblastoma cell lines; and to identify alterations in various signaling pathways that are paramount to their growth and maintenance. Furthermore, we targeted the EMP2-HIF1α axis, a proposed regulator of VEGF expression, to determine its effects on cell viability. METHODS Three primary tumor glioblastoma cell lines were generated and cultured under adherent or non-adherent growth conditions. Sequencing was performed on the Illumina HiSeq3000 system, and gene counts were normalized by TMM. A pair-wise statistical analysis of over 20,000 genes was performed between the two conditions. A p-value &amp;lt; 0.05 was considered statistically significant. RESULTS After 72 hours of growth under 3D conditions, primary glioblastoma cells show an increase in stem-like properties, measured via an upregulation of SOX2 and nestin. RNA sequencing demonstrated a significant increase in expression of the following transcripts in 3D conditions compared to those grown on adherent plates: VEGF-A, EGFR, PDGFR-A, FGFR3, and TGFB2. Treatment with anti-EMP2 monoclonal antibodies significantly reduced cellular proliferation. CONCLUSION Our results demonstrate that neurospheres upregulate growth factor pathways to enable their survival in 3D conditions, suggesting an inherently different genetic landscape between differentiated tumor cells and GSCs. Future studies will investigate the cellular mechanisms responsible for upregulation of these genes; and to ultimately design more effective targeted therapeutic agents.
PATH-02. ANALYSIS OF MICRORNA EXPRESSION IN BRAIN METASTASES USING NEXT-GENERATION SEQUENCING
Authors: Radim Jancalek, Marek Vecera, Frantisek Siegl, Jiri Sana, Karolina Trachtova, Michal Hendrych, Vaclav Vybihal, Martin Smrcka, Marketa Hermanova, Tomas Kazda, Ondrej Slaby
Journal: Neuro-Oncology (2022)

Abstract BACKGROUND Brain metastases (BMs) are intracranial tumors that frequently occur in adult cancer patients. Because the prognosis of patients with BM individually varies, it would be useful to improve prognostic scoring tools by including new high-performance biomarkers. MicroRNAs (miRNAs) appear to be promising in this regard as they are highly stable and, thus, suitable for both next-generation sequencing (RNA-Seq) and retrospective analyses in formalin-fixed and paraffin-embedded (FFPE) tissues.Material and METHODS Total RNA enriched for miRNAs was isolated from 71 freshly frozen histopathologically confirmed BMs with origin in 5 tumor types (ca lung - 37%, melanoma - 23%, ca breast - 18%, RCC - 15%, CRC - 7%) using mirVana miRNA Isolation Kit (Thermo Fisher Scientific). Sequencing libraries were prepared from RNA using the QIAseq miRNA Library Kit (Qiagen) and sequenced using the NextSeq 500 platform (Illumina). The miRNA molecules were subsequently transcribed from total RNA samples isolated from a retrospective set of 119 FFPE tissues using the TaqMan Advanced miRNA cDNA Synthesis Kit, and the expression of selected miRNAs was validated in a pilot experiment by qPCR using TaqMan Fast Advanced Master Mix and appropriate TaqMan MicroRNA Assays (all from Thermo Fisher Scientific). RESULTS The differential analysis identified 373 miRNAs with significantly different expression among the 5 BMs groups (p&amp;lt; 0.001). A molecular classifier based on the expression of 32 miRNAs was able to classify all samples correctly. Out of these, seven, including miR-122-5p, miR-141-3p, miR-146a-5p, miR-194-5p, miR-200c-3p, miR-211-3p, and miR-215-5p, were chosen for subsequent validation and their significantly different expression in 5 BMs groups was validated. CONCLUSIONS Presented results confirm the importance of studying dysregulated miRNA expression in BM and the diagnostic potential of validated miRNAs. The study was prepared with the grant support of the Ministry of Health of the Czech Republic - grant No. NV18-03-00398.
SURG-05. SUPERVISED MACHINE LEARNING IDENTIFIES RISK FACTORS ASSOCIATED WITH LEPTOMENINGEAL DISEASE AFTER SURGICAL RESECTION OF BRAIN METASTASES
Authors: Ramin A Morshed, Satvir Saggi, Daniel Cummins, Jacob S Young, Jennifer Viner, Javier Villanueva-Meyer, Ezequiel Goldschmidt, Lauren Boreta, Steve Braunstein, Edward Chang, Michael McDermott, Mitchel S Berger, Philip Theodospoulos, Shawn L Hervey-Jumper, Manish Aghi, Mariza Daras
Journal: Neuro-Oncology (2022)

Abstract INTRODUCTION Predictors of postoperative leptomeningeal disease (LMD) after resection of brain metastases (BMs) are not well defined. OBJECTIVE This study examined rates and predictors of LMD, including subtypes, in patients who underwent resection of a BM followed by postoperative radiation.Method: A retrospective, single-center study was conducted examining overall LMD, classical LMD (cLMD), and nodular LMD (nLMD) risk. Logistic regression and a Cox proportional hazards analyses were performed to identify risk factors associated with LMD. Random forest models were constructed to predict LMD and differentiate cLMD versus nLMD. Accuracy and the area under the receiver operating characteristic curve (AUROC) were calculated to evaluate the models.Result: Of the 217 patients in the cohort, 47 (21.7%) developed postoperative LMD with 19(8.8%) cLMD cases and 28(12.9%) nLMD cases . Six-, 12-, and 24-month LMD-free survival rates were 92.3%, 85.6%, and 71.4%, respectively. Patients with cLMD had worse survival outcomes from LMD diagnosis compared to nLMD (2.4 vs 6.9 mo, Log-rank p=0.02), and treatment of LMD was associated with improved survival for both cLMD and nLMD subtypes. Multivariate Cox hazard analysis identified cerebellar/insular/occipital location (HR 3.25, 95% CI 1.73-6.11, p=0.0003), absence of extracranial disease (HR 2.49, 95% CI 1.27-4.88, p=0.008), and ventricle contact (HR 2.82, 95% CI 1.5-5.3, p=0.001) to be associated with postoperative LMD. A predictive model using random forest analysis with an AUROC of 0.87 in a test cohort identified tumor location, systemic disease status, and tumor volume as the most important factors associated with LMD. Both regression analysis and random forest analysis identified postoperative systemic therapy exposure as the main factor differentiating cLMD from nLMD development. CONCLUSION Tumor location, absence of extracranial disease at the time of surgery, contact with a ventricle, and increased tumor volume are associated with LMD. Classical LMD is associated with worse prognosis compared to nLMD.